Natural history of small asymptomatic kidney and residual stones over a long‐term follow‐up: systematic review over 25 years

Abstract

Objective To systematically review the natural history of small asymptomatic kidney and residual stones, as the incidental identification of small, asymptomatic renal calculi has risen with increasing use of high‐resolution imaging. Materials and methods We reviewed the natural history of small asymptomatic kidney and residual stones using the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) methodology. We searched MEDLINE, Scopus, EMBASE, EBSCO, Cochrane library and Clinicaltrials.gov using themes of ‘asymptomatic’, ‘nephrolithiasis’, ‘observation’, ‘symptoms’, ‘admission’, ‘intervention’ and similar allied terms for all English language articles from 1996 to 2020 (25 years). Inclusion criteria were studies with ≥50 patients, stones ≤10 mm, and a mean follow‐up of ≥24 months. Primary outcomes were occurrence of symptoms, emergency admission, and interventions. Results Our literature search returned 2247 results of which 10 papers were included in the final review. Risk of symptomatic episodes ranged from 0% to 59.4%. Meta‐analysis did not identify any significant difference in the likelihood of developing symptoms when comparing stones <5 mm to those >5 mm, nor those <10 mm to those >10 mm. Risk of admission varied from 14% to 19% and the risk of intervention from 12% to 35%. Meta‐analysis showed a significantly decreased likelihood of intervention for stones <5 vs >5 mm and <10 vs >10 mm. Studies had variable risk of bias due to heterogeneous reporting of outcome measures with significant likelihood that observed differences in results were compatible with chance alone (Symptoms: I2=0%, Cochran’s Q = 3.09, P = 0.69; Intervention: I2=0%, Cochran’s Q = 1.76, P = 0.88). Conclusions The present systematic review indicates that stone size is not a reliable predictor of symptoms; however, risk of intervention is greater for stones >5mm vs <5 mm and >10 vs <10 mm. This review will inform urologists as they discuss management strategies with patients who have asymptomatic renal stones and offer insight to committees during the development of evidence‐based guidelines.

Optimal Delivery of Follow-Up Care for the Prevention of Stone Recurrence in Urolithiasis Patients: Improving Outcomes

“… 52 However, heterogeneity among studies does not permit safe conclusions to be drawn. Intervention rates were found to be significantly lower for stones <5 mm compared to >5 mm and those <10 mm compared to >10 mm, 51 while upper pole stones, patients <50 years old and those with prior stone-related procedures were more likely to require intervention in the future. 53 , 54 Therefore, simple follow-up can be proposed to patients with asymptomatic renal stones, especially those with <5–10 mm size, non-upper pole location and in patients without a history of surgery related to urolithiasis.…”

“…Recently, Lovegrove et al performed a systematic review and meta-analysis to appraise the literature regarding data on small, asymptomatic renal stones. 51 Although several studies suggest that stone size is a predictor of symptom occurrence (pain, fever, infection, hematuria), with stones >5 mm showing greater chance of causing symptoms, 52 pooled analysis did not detect significant difference for symptom occurrence in stones <5 mm compared to >5 mm, or stones <10 mm compared to >10 mm. 51 Lower calyx location and right-sided stones may have a protective role.…”

“… 51 Although several studies suggest that stone size is a predictor of symptom occurrence (pain, fever, infection, hematuria), with stones >5 mm showing greater chance of causing symptoms, 52 pooled analysis did not detect significant difference for symptom occurrence in stones <5 mm compared to >5 mm, or stones <10 mm compared to >10 mm. 51 Lower calyx location and right-sided stones may have a protective role. 52 However, heterogeneity among studies does not permit safe conclusions to be drawn.…”

The Relationship Between Renal Stones and Primary Aldosteronism

“…Another systemic review included an asymptomatic kidney stone article over 25 years and indicated that stone size was not a reliable predictor of symptoms, but the need for intervention was linked to stone size. Stones >5 mm have 36% greater risk of intervention compared with stones of <5 mm ( 49 ). In the present study, the mean stone size in PA patients was 6.5 mm, which was greater than 5 mm; hence, the possibility of the need for stone intervention was higher than that in essential hypertension patients.…”

Duration of Follow-up and Timing of Discharge from Imaging Follow-up, in Adult Patients with Urolithiasis After Surgical or Medical Intervention: A Systematic Review and Meta-analysis from the European Association of Urology Guideline Panel on Urolithiasis

“…1). According to the inclusion criteria, we finally included 50 studies for analysis , while 11 studies were excluded due to referring only to the observation of stone patients, which was recently analyzed and summarized by Lovegrove and Geraghty [67] in their meta-analysis. Moreover, 17 studies 1 and 2 for stone-free patients and patients with residuals, respectively.…”